Hello all. I have read various threads here on this topic and still don't know which of the two - LS400 or Supra TT caliper swap will clear my wheels. The specs of my wheels are: Lexus Forged F Sport, 10 spoke, 19 x 8.0", offset: 40 mm (pictures attached). I am leaning towards Supra TT as this one does not need a RCA block in the front. However, want to avoid using spacers. Can someone who has done the Supra upgrade, please help.







Also, how much I could afford to lower (on these wheels) for visual appeal but without issues? Tires are Michelin Pilot Sport A/S 3 (245/40ZR19XL 98Y B). I know I can always experiment but I would like to learn from the experience here.

TIA. Cheers.

 

From the photos look like it should clear both LS and Supra calipers. If your wheels fit the LS400 and/or IS350 or IS F then it would clear for sure since they all have big calipers. I did the LS400 front brake calipers upgrade and used the RCA which lowers the car by 1" front end. So if you wanted to lower the front you might want to do the LS400 upgrade.

 

Thanks for a prompt response. Did you have to modify anything else in the front suspension when you added the RCA block since you lowered it by an inch? How difficult it was to add the block?

Any other changes to the suspension to compensate? How does you car ride.

Thanks once again. Cheers.

 

There's no difference relative to the ride to my feel of, it's actually pretty easy to install the RCA and no suspension changes, I didn't even do an alignment and I don't think you would need one, you do need to trim the brake dust shield since the caliper is bigger and the rotor larger as well, overall no surprises. I believe there is a write up here from someone's build, maybe someone can remember who and post a link to it for you.

 

Sorry for the stupid questions, but from my understanding the RCA kit allows you to lower the suspension but keep the OEM shocks and springs, correct? What does RCA stand for? What kit do you recommend? Is the kit only for front, or can it also be used on the rear? Will the RCA kit work with the Supra TT Calipers and rotors, as this is what i'm in the process of installing. I ask these questions, as my next mod will be either coilovers, or this RCA kit if it allows adjusting ride height with OEM components. Thanks in advance.

 

I went and checked the site where I made the purchase and found the following write up - "This wheel fits all Lexus IS250/350 including the IS-C, as well as the GS350.

Keep in mind; these wheels are compatible with the full catalog of F-Sport Performance Accessories, including the F-Sport High Performance Brake Kit."

Is this good enough to assume that I can go with either? I really like the looks of your LS400 caliper setup and if RCA block installation is easy then I may just go with LS400 calipers install

Anyone tried using bigger rotors than OEM LS rotors? If yes, where to look for a bracket?

Finally, what to do with the rear once the front is upgraded? Any options to keep the braking balanced....and similar visual appearance?

Thanks in advance.

 

RCA stands for Roll Center Adjuster, it's actually a spacer between the lower control arm to the wheel hub, since the LS400 front calipers is bigger and when turning the wheel will hit the lower control arm's knuckle therefore the RCA lowers the knuckle and clear the caliper from hitting. Now I am not sure if you need them with Supra turbo calipers but yes, it's only for front end and you can still install coilover with no ill effect, matter of fact that's what I'm going to fo next as well.

 

I would assume that the wheels would fit over the either calipers.
I don't think you can use bigger rotors than the OEM LS400 rotors since the arc will be different, as for the rear, I think there's not a kit that would be simple bolt on as the fronts and I have not seen any DIY regarding it either. The cars have ABS so it should balance well.

 

One more thing to add.....If RCA block is used in the front then one needs to lower the back either with coilovers OR use a RCA block for the back too.

Based on what I have read here, Supra calipers do not need a RCA block.

 

Supra calipers don't need them, that's correct, and I have not found rear RCA for our car to balance the height but I am doing coilover as my next upgrade.

 

This shows a front and rear kit for the ALL SC430... not sure how much drop you are looking for but 30mm is a little over and inch. I would prefer going with RCA blocks compared to coilovers, to be honest. Less invasive install and adjustment. Would the RCA front and rear blocks work with Supra Calipers, Supra Rotors, OEM Springs, and OEM shocks?

http://lexi-imports.blogspot.com/

 

The RCA kit works with or without upgrade of calipers so you can lower the car with them. The rear kit has camber adjusting function which I don't like personally. It's just one more thing that could move around and alter the settings. As of now my rear tires are wearing even and I'm trying not to mess with it. As my understanding the rear kits would benefit if you were wanted to put air ride on the car or you were to do a low rider which you then will need to have more adjustment on the rear cambers. I could be wrong but that's my understanding of the true function of them.

 

Shawn,
Supra calipers upgrade do NOT need RCA blocks, necessarily.....unless you want to lower the car by using the RCA blocks.

I personally am torn between using the RCA in the front and do the LS400 upgrade (for better looks than Supra) and then use RCA in the back (or coilovers) to balance OR use Supra calipers for the upgrade (without RCA) and use coilovers to lower the car, all around. I go back and forth. Right now, I am thinking of putting Supra calipers and use coilovers all around to lower the car. Why? Because of the mileage on my car, I need to change the shocks anyway PLUS the coilovers will give me the flexibility of adjusting the ride height. I don't want to put much stress on the suspension links by lowering the car too much, probably will end up around 0.8" or so (keep it less than an inch). With RCAs and LS400 calipers, I would have to lower the car by an inch or more....and it's FIXED! Does my logic make sense?

Why are you against coilovers?

Cheers.

 

Thanks for the clarification guys. I really do appreciate it. I'm not against coilovers, at all. Honestly, I wanted coilovers for the longest time but I can't truly afford them at the moment or in the near future, especially since I have a lot of funds sunk into the Supra BBK kit I'm installing soon. I thought for the time being I could use the RCA kits for front and rear to give me a little drop until my financial situation improves, and allow me to keep the OEM shocks and springs since I have a lot of life left with less than 50k miles on my car. I also feel that the install of the coilovers would cost more in labor vs the RCA kit install. Just me thinking out loud, but still up in the air on which way to go...

So i guess my following question is this... if I went with the 30mm RCA kit for the front and rear, would I have suspension problems (as someone in a previous post noted snapped end links after lowering)? I'm running the upgraded front and rear sway bar setup with the OEM links and PU bushings and 20" rims. Thanks in advance for any help or suggestions.

 

What are the specs on the SC430 OEM?